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Biotin Attachment Domain-Containing Proteins Irreversibly Inhibit Acetyl CoA Carboxylase.
- Source :
-
Plant Physiology . May2018, Vol. 177 Issue 1, p208-215. 8p. - Publication Year :
- 2018
-
Abstract
- The first committed step in fatty acid synthesis is mediated by acetyl-CoA carboxylase (ACCase), a biotin-dependent enzyme that carboxylates acetyl-CoA to produce malonyl-CoA. ACCase can be feedback regulated by short-term or long-term exposure to fatty acids in the form of Tween 80 (predominantly containing oleic acid), which results in reversible or irreversible ACCase inhibition, respectively. Biotin attachment domain-containing (BADC) proteins are inactive analogs of biotin carboxyl transfer proteins that lack biotin, and their incorporation into ACCase down-regulates its activity by displacing active (biotin-containing) biotin carboxyltransferase protein subunits. Arabidopsis (Arabidopsis thaliana) lines containing T-DNA insertions in BADC1, BADC2, and BADC3 were used to generate badc1 badc2 and badc1 badc3 double mutants. The badc1 badc3 mutant exhibited normal growth and development; however, ACCase activity was 26% higher in badc1 badc3 and its seeds contained 30.1% more fatty acids and 32.6% more triacylgycerol relative to wild-type plants. To assess whether BADC contributes to the irreversible phase of ACCase inhibition, cell suspension cultures were generated from the leaves of badc1 badc3 and wild-type plants and treated with 10 mm Tween 80. Reversible ACCase inhibition was similar in badc1 badc3 and wild-type cultures after 2 d of Tween 80 treatment, but irreversible inhibition was reduced by 50% in badc1 badc3 relative to wild-type plants following 4 d of Tween 80 treatment. In this study, we present evidence for two important homeostatic roles for BADC proteins in down-regulating ACCase activity: by acting during normal growth and development and by contributing to its long-term irreversible feedback inhibition resulting from the oversupply of fatty acids. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 00320889
- Volume :
- 177
- Issue :
- 1
- Database :
- Academic Search Index
- Journal :
- Plant Physiology
- Publication Type :
- Academic Journal
- Accession number :
- 129435237
- Full Text :
- https://doi.org/10.1104/pp.18.00216